Salted chocolate mousse

Instructions

1. Put the chocolate, cocoa powder, coffee, vanilla and 4 tbsp water in a heatproof bowl. Bring a small pan of water to a simmer over a medium-low heat and set the bowl of chocolate over the water, taking care not to let the base touch the water. Stir occasionally until the mixture is melted and combined then remove from the heat and set aside to cool slightly.
2. In a bowl, whisk the egg whites to stiff peaks, then add the sugar and whisk again until the meringue mixture is thick and glossy.
3. Stir 50g of the crème fraîche into the chocolate mixture, then stir in one-third of the meringue mixture and all of the salt. Using a large metal spoon or spatula, very gently fold in the remaining meringue mixture, taking care not to overmix.
4. Divide between six bowls, cups or dessert pots and then chill for at least 3 hours, or overnight.
5. Serve topped with the remaining crème fraîche and dusted with the extra cocoa powder.